scholarly journals NOX4 PROTECTIVE EFFECT IN ENDOTHELIAL FUNCTION INVOLVES ACTIVATION OF TRANSIENT RECEPTOR POTENTIAL MELASTATIN 2 (TRPM2) CATION CHANNEL

2021 ◽  
Vol 39 (Supplement 1) ◽  
pp. e16
Author(s):  
Rheure Alves-Lopes ◽  
Karla Neves ◽  
Augusto Montezano ◽  
Rhian Touyz
Life ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 397
Author(s):  
Andras Szollosi

The transient receptor potential melastatin (TRPM) family belongs to the superfamily of TRP ion channels. It consists of eight family members that are involved in a plethora of cellular functions. TRPM2 is a homotetrameric Ca2+-permeable cation channel activated upon oxidative stress and is important, among others, for body heat control, immune cell activation and insulin secretion. Invertebrate TRPM2 proteins are channel enzymes; they hydrolyze the activating ligand, ADP-ribose, which is likely important for functional regulation. Since its cloning in 1998, the understanding of the biophysical properties of the channel has greatly advanced due to a vast number of structure–function studies. The physiological regulators of the channel have been identified and characterized in cell-free systems. In the wake of the recent structural biochemistry revolution, several TRPM2 cryo-EM structures have been published. These structures have helped to understand the general features of the channel, but at the same time have revealed unexplained mechanistic differences among channel orthologues. The present review aims at depicting the major research lines in TRPM2 structure-function. It discusses biophysical properties of the pore and the mode of action of direct channel effectors, and interprets these functional properties on the basis of recent three-dimensional structural models.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Iordan Iordanov ◽  
Csaba Mihályi ◽  
Balázs Tóth ◽  
László Csanády

Transient Receptor Potential Melastatin 2 (TRPM2) is a Ca2+-permeable cation channel essential for immunocyte activation, insulin secretion, and postischemic cell death. TRPM2 is activated by ADP ribose (ADPR) binding to its C-terminal cytosolic NUDT9-homology (NUDT9H) domain, homologous to the soluble mitochondrial ADPR pyrophosphatase (ADPRase) NUDT9. Reported ADPR hydrolysis classified TRPM2 as a channel-enzyme, but insolubility of isolated NUDT9H hampered further investigations. Here we developed a soluble NUDT9H model using chimeric proteins built from complementary polypeptide fragments of NUDT9H and NUDT9. When expressed in E.coli, chimeras containing up to ~90% NUDT9H sequence remained soluble and were affinity-purified. In ADPRase assays the conserved Nudix-box sequence of NUDT9 proved essential for activity (kcat~4-9s-1), that of NUDT9H did not support catalysis. Replacing NUDT9H in full-length TRPM2 with soluble chimeras retained ADPR-dependent channel gating (K1/2~1-5 μM), confirming functionality of chimeric domains. Thus, TRPM2 is not a 'chanzyme'. Chimeras provide convenient soluble NUDT9H models for structural/biochemical studies.


2020 ◽  
Author(s):  
Siyuan Zhao ◽  
Yevgen Yudin ◽  
Tibor Rohacs

ABSTRACTTransient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+ permeable non-selective cation channel activated by heat and chemical agonists such as pregnenolone sulfate and CIM0216. TRPM3 mutations in humans were recently reported to be associated with intellectual disability and epilepsy; the functional effects of those mutations however were not reported. Here we show that both disease-associated mutations of TRPM3 render the channel overactive, but likely via different mechanisms. The Val to Met substitution in the S4-S5 loop induced a larger increase in basal activity and agonist sensitivity at room temperature than the Pro to Gln substitution in the extracellular segment of S6. In contrast, heat activation was increased more by the S6 mutant than by the S4-S5 segment mutant. Both mutants were inhibited by the TRPM3 antagonist primidone, suggesting a potential therapeutic intervention to treat this disease.


2013 ◽  
Vol 25 (11) ◽  
pp. 2163-2175 ◽  
Author(s):  
Alvaro Yogi ◽  
Glaucia E. Callera ◽  
Sarah O'Connor ◽  
Tayze T. Antunes ◽  
William Valinsky ◽  
...  

Hypertension ◽  
2020 ◽  
Vol 75 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Rhéure Alves-Lopes ◽  
Karla B. Neves ◽  
Aikaterini Anagnostopoulou ◽  
Francisco J. Rios ◽  
Silvia Lacchini ◽  
...  

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Siyuan Zhao ◽  
Yevgen Yudin ◽  
Tibor Rohacs

Transient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+ permeable non-selective cation channel activated by heat and chemical agonists such as pregnenolone sulfate and CIM0216. TRPM3 mutations in humans were recently reported to be associated with intellectual disability and epilepsy; the functional effects of those mutations, however, were not reported. Here, we show that both disease-associated mutations in the human TRPM3 render the channel overactive, but likely via different mechanisms. The Val to Met substitution in the S4-S5 loop induced a larger increase in basal activity and agonist sensitivity at room temperature than the Pro to Gln substitution in the extracellular segment of S6. In contrast, heat activation was increased more by the S6 mutant than by the S4-S5 segment mutant. Both mutants were inhibited by the TRPM3 antagonist primidone, suggesting a potential therapeutic intervention to treat this disease.


Sign in / Sign up

Export Citation Format

Share Document